Fuel Economy Converter
Seamlessly convert between MPG and L/100km with our interactive efficiency tracking tool.
Miles per Gallon
Liters per 100 Kilometers
Efficiency Analysis
EXCELLENT
Based on standard passenger vehicle averages
E ————— F
British vs US MPG
Note: An Imperial (UK) Gallon is larger than a US Gallon. multiply US MPG by 1.2 for the approximate UK equivalent.
Standard Conversion
L/100km and MPG have an inverse relationship. As MPG goes up, L/100km goes down. 235.215 / MPG = L/100km.
Fuel Economy Converter: MPG, L/100km, km/L
Instantly convert vehicle fuel efficiency ratings between US MPG, UK MPG, Liters per 100km, and Kilometers per Liter. Essential for international vehicle comparison.
The automotive world is sharply divided in how it measures fuel efficiency. A driver in the United States evaluates a vehicle in Miles Per Gallon (MPG), while an engineer in Europe looks at Liters per 100 Kilometers (L/100km). This creates massive confusion when researching imported vehicles, reading international automotive reviews, or renting cars abroad. The Fuel Economy Converter bridges this gap, instantly translating these wildly different measurement systems so you can accurately compare vehicle efficiency across borders.
Volume vs. Distance Metrics
Fuel efficiency is measured using two fundamentally opposed philosophies. The US system (MPG) measures Distance per Volume: "How far can I drive on this specific amount of fuel?" In this system, a higher number is always better.
The European metric system (L/100km) measures Volume per Distance: "How much fuel do I need to burn to travel a set distance of 100km?" In this system, a lower number is better, because it means the car burned less fuel over the standardized distance. Converting between these two systems is not a simple multiplication; it requires an inverse calculation, which makes mental math almost impossible.
The US vs. UK Gallon Trap
Perhaps the most dangerous trap for consumers reading international car reviews is the difference between an American gallon and an Imperial (UK) gallon. A US liquid gallon is 3.785 liters, while an Imperial gallon is significantly larger at 4.546 liters.
Because the UK gallon is larger, a British car will always report a much higher MPG number than the exact same car tested in the US. A car getting 40 MPG in a UK review is only getting about 33 MPG in US terms. Our converter explicitly separates US MPG and UK MPG to prevent this exact misunderstanding.
How to Use the Converter
Using the tool is effortless. Simply select your starting measurement unit (e.g., L/100km) and input the efficiency rating of the vehicle. The tool will simultaneously output the equivalent values in US MPG, UK MPG, and km/L.
Once you have converted the efficiency rating into a format you understand, you can use that specific number in our Fuel Cost Calculator to accurately budget for an upcoming road trip or daily commute.
The Shift to Electric (MPGe)
As the world transitions to Electric Vehicles (EVs), traditional liquid volume measurements become obsolete. To allow consumers to compare a Tesla to a Toyota, regulators created "MPGe" (Miles Per Gallon equivalent), which translates the energy contained in a battery (kWh) into the energy equivalent of a gallon of gasoline.
For definitive, government-verified fuel efficiency data across internal combustion, hybrid, and fully electric vehicles, consult the databases provided by the Environmental Protection Agency (EPA).
Expert Insights & FAQs
Quick answers to common questions about this utility.
Why does the rest of the world use L/100km instead of km/L?
Measuring 'Volume per Distance' (L/100km) makes calculating the true cost of a trip much easier. If a trip is 500km and your car uses 8L/100km, you instantly know the trip will take 40 liters of fuel. MPG requires division to figure out the required fuel volume.
Is 5 L/100km considered good fuel economy?
Yes, 5 L/100km is excellent. It translates to roughly 47 US MPG. This level of efficiency is typically only seen in small, modern hybrid vehicles or extremely efficient compact diesel cars.
Why did a car review from the UK say the car gets 60 MPG, but the US site says 50 MPG?
They are both mathematically correct! The British Imperial Gallon is about 20% larger than the US Gallon. Therefore, the car physically travels 20% further on a British gallon. You must always check which 'gallon' an article is referencing.